Ported fresh_when into a ConditionalGet module

actionpack/lib/action_controller/new_base.rb

@@ -1,5 +1,6 @@
 module ActionController
   autoload :Base,                 "action_controller/new_base/base"
+  autoload :ConditionalGet,       "action_controller/new_base/conditional_get"
   autoload :HideActions,          "action_controller/new_base/hide_actions"
   autoload :Http,                 "action_controller/new_base/http"
   autoload :Layouts,              "action_controller/new_base/layouts"

actionpack/lib/action_controller/new_base/base.rb

@@ -10,6 +10,7 @@ module ActionController
     use ActionController::UrlFor
     use ActionController::Renderer
     use ActionController::Layouts
+    use ActionController::ConditionalGet
     
     # Legacy modules
     include SessionManagement

actionpack/lib/action_controller/new_base/conditional_get.rb

@@ -0,0 +1,42 @@
+module ActionController
+  module ConditionalGet
+    
+    # Sets the etag, last_modified, or both on the response and renders a
+    # "304 Not Modified" response if the request is already fresh.
+    #
+    # Parameters:
+    # * <tt>:etag</tt>
+    # * <tt>:last_modified</tt> 
+    # * <tt>:public</tt> By default the Cache-Control header is private, set this to true if you want your application to be cachable by other devices (proxy caches).
+    #
+    # Example:
+    #
+    #   def show
+    #     @article = Article.find(params[:id])
+    #     fresh_when(:etag => @article, :last_modified => @article.created_at.utc, :public => true)
+    #   end
+    #
+    # This will render the show template if the request isn't sending a matching etag or
+    # If-Modified-Since header and just a "304 Not Modified" response if there's a match.
+    #    
+    def fresh_when(options)
+      options.assert_valid_keys(:etag, :last_modified, :public)
+
+      response.etag          = options[:etag]          if options[:etag]
+      response.last_modified = options[:last_modified] if options[:last_modified]
+      
+      if options[:public] 
+        cache_control = response.headers["Cache-Control"].split(",").map {|k| k.strip }
+        cache_control.delete("private")
+        cache_control.delete("no-cache")
+        cache_control << "public"
+        response.headers["Cache-Control"] = cache_control.join(', ')
+      end
+
+      if request.fresh?(response)
+        head :not_modified
+      end
+    end    
+    
+  end
+end

actionpack/lib/action_controller/new_base/testing.rb

@@ -7,6 +7,7 @@ module ActionController
       @_response = response
       ret = process(request.parameters[:action])
       @_response.body = self.response_body
+      @_response.prepare!
       set_test_assigns
       ret
     end

actionpack/test/new_base/etag_test.rb

@@ -0,0 +1,47 @@
+require File.join(File.expand_path(File.dirname(__FILE__)), "test_helper")
+
+module Etags
+  
+  class BasicController < ActionController::Base
+    
+    self.view_paths = [ActionView::Template::FixturePath.new(
+      "etags/basic/base.html.erb" => "Hello from without_layout.html.erb",
+      "layouts/etags.html.erb"    => "teh <%= yield %> tagz"
+    )]
+    
+    def without_layout
+      render :action => "base"
+    end
+    
+    def with_layout
+      render :action => "base", :layout => "etag"
+    end
+    
+  end
+  
+  class TestBasic < SimpleRouteCase
+    describe "Rendering without any special etag options returns an etag that is an MD5 hash of its text"
+    
+    test "an action without a layout" do
+      get "/etags/basic/without_layout"
+      body = "Hello from without_layout.html.erb"
+      assert_body body
+      assert_header "Etag", etag_for(body)
+      assert_status 200
+    end
+    
+    test "an action with a layout" do
+      get "/etags/basic/with_layout"
+      body = "teh Hello from without_layout.html.erb tagz"
+      assert_body body
+      assert_header "Etag", etag_for(body)
+      assert_status 200      
+    end
+    
+    def etag_for(text)
+      %("#{Digest::MD5.hexdigest(text)}")
+    end
+  end
+  
+  
+end